1-Fluoronaphthalene: detection method, applications and safety

General Description

1-Fluoronaphthalene is a synthetic organic compound that belongs to the group of fluorinated aromatic hydrocarbons and can be detected and quantified using a reversed-phase high-performance liquid chromatography method. This synthetic organic compound is commonly employed as a solvent additive in organic solar cell research to enhance power conversion efficiency (PCE) and overall performance. It is crucial to handle this substance with caution by avoiding inhalation, direct contact with skin or eyes, and ensuring proper ventilation. Protective equipment should be worn during handling procedures.

Figure 1. 1-Fluoronaphthalene

Detection method

A reversed-phase high-performance liquid chromatography method was developed to detect and measure 1-fluoronaphthalene and its process-related impurities in duloxetine hydrochloride active pharmaceutical ingredient (API). The impurity profile of the substance is crucial for safety assessment and manufacturing processes. The method utilizes a Symmetry C18 column and two mobile phases: mobile phase A, consisting of a mixture of 0.01 Μ KH2PO4 buffer (pH 2.5 ± 0.1), methanol, and acetonitrile; and mobile phase B, a mixture of methanol and acetonitrile. The analytes are monitored using a photo diode array detector at a wavelength of 230 nm. The method has a linear concentration range of 0.075-5.000 μg/mL for 1-aminonaphthalene, 0.150-5.000 μg/mL for 1-nitronaphthalene, 0.3125-5.000 μg/mL for naphthalene, and 0.3125-5.000 μg/mL for 2-fluoronaphthalene. The method has high precision and accuracy, with correlation coefficients above 0.9997 for each impurity. The proposed method was validated according to International Conference on Harmonization guidelines and showed mean recoveries in the range of 90-110%. Overall, this method provides a simple and precise approach for the detection of 1-fluoronaphthalene, a key starting material in the synthesis of duloxetine hydrochloride API. ¹

Applications

1-Fluoronaphthalene is used as a solvent additive in organic solar cell (OSC) research to improve the power conversion efficiency (PCE) and performance of the devices. In the first study mentioned, 1-Fluoronaphthalene was demonstrated to assist in the fibrillization process of a non-fullerene acceptor (NFA) called L8-BO. This resulted in the formation of fine fibrils with a compact polycrystal structure, enhancing light absorption, charge transport, and collection properties. Incorporating these fibrils into the active layer of the OSCs led to an unprecedented PCE increase from 16.0% to 19.0%. Additionally, 1-Fluoronaphthalene was incorporated into the acceptor material Y6, along with the use of an n-octane additive in the donor material D18-Cl, to achieve precise control over the morphology of the active layer. This approach resulted in improved phase separation morphology and enhanced crystallization of the materials, leading to higher PCEs compared to control devices. Furthermore, by combining n-octane doping in the donor and FN in the acceptor, a more desirable vertical morphology was achieved, resulting in an excellent PCE of 18.16%, one of the highest efficiencies reported for OSCs fabricated using the layer-by-layer spin-coating method. Overall, the addition of 1-fluoronaphthalene as a solvent additive in these studies demonstrated its effectiveness in improving the performance of organic solar cells by enhancing the intermolecular packing, inducing self-assembly, and controlling the morphology of the active layer. ^2,3

Safety

1-Fluoronaphthalene poses potential safety risks and precautions should be taken when handling the substance. To ensure safety, it is important to avoid the formation of dust and prevent inhalation of mist, gas, or vapors. Direct contact with the skin and eyes should be avoided, and personal protective equipment should be worn. Chemical impermeable gloves are recommended for handling. Adequate ventilation is necessary to minimize exposure. All potential ignition sources should be removed from the area. In case of a spill or leak, personnel should be evacuated to safe areas, and individuals should be kept away from the spill/leak area and positioned upwind. These safety measures are crucial for handling 1-Fluoronaphthalene properly and minimizing potential risks. ⁴

Reference

1. Karagiannidou EG, Bekiari ET, Vastardi EI. A Validated RP-HPLC Method for the Analysis of 1-Fluoronaphthalene and Its Process-Related Impurities. J Chromatogr Sci. 2015 Sep;53(8):1296-1302.

2. Li D, Deng N, Fu Y, Guo C, Zhou B, Wang L, Zhou J, Liu D, Li W, Wang K, Sun Y, Wang T. Fibrillization of Non-Fullerene Acceptors Enables 19% Efficiency Pseudo-Bulk Heterojunction Organic Solar Cells. Adv Mater. 2023 Feb;35(6):e2208211.

3. Li X, Zhu R, He Z, Du X, Lin H, Zheng C, Yang G, Chen Z, Tao S. Additive-Induced Vertical Component Distribution Enables High-Performance Sequentially Cast Organic Solar Cells. ACS Appl Mater Interfaces. 2022 Jun 8;14(22):25842-25850.

4. Substance Infocard: 1-Fluoronaphthalene. European Chemicals Agency, EC: 206-287-0.